Fast multipole method for scattering from an arbitrary perfectly conducting target above or below a lossy half space

The fast multipole method (FMM) was originally developed for perfectly electric conducting (PEC) targets in free space. Here, the FMM is extended to the scattering from a PEC target above or below a lossy half space. The "near" terms are handled via a method-of-moments (MoM) analysis, wherein the half-space Green's function is evaluated through application of the method of complex images. The "far" interactions utilize an approximation to the Green's function dyadic. The algorithm is validated through comparison with rigorous MoM results.